Perhaps the most common of the prior known flush control valves for urinals employs a lever, or disk, which serves as the manually operated handle. In these installations the handle may be selectively tilted by the user to initiate a flush. With either type of handle that portion thereof disposed interiorly of the flush control valve engages, or constitutes a component of, the flush actuating and control mechanism. In such prior known arrangements the actuating and control mechanism, including any timing assemblies, is disposed directly within the flow path of the flush fluid as it passes through the flush control valve. Such exposure subjects the actuating and control mechanisms to corrosion and/or accretion of contaminants suspended within, or carried in solution by, the flush fluid. Corrosion and the accretion of contaminants can cause malfunctions or erratic operation of the valve.
Flush control valves for urinals have, heretofore, also widely employed manually operated push buttons to initiate the flush. Here, too, that portion of the push button mechanism disposed within the flush control valve engages, or constitutes a component of, the actuating and control mechanism which lies in direct contact with the flush fluid passing through the flush control valve. The actuating and control mechanisms, including any timing assemblies, of these valves are, therefore, also subject to corrosion and contaminant accretion which can cause malfunctions or erratic operation of the flush control valve.
The vast majority of the prior known flush control valves for urinals, and the like, irrespective of whether they employ manually operated handles, disks or push buttons, utilize an orifice, or other restricted passage, in the timing assembly to effect the timing control for determining the flush cycle. These orifices, or restrictions, have heretofore been routinely disposed within the flow path of the flush fluid and are, therefore, particularly subject to malfunctions caused by particles suspended in the flush fluid. Many prior known flush control valves tacity evidence that their flush cycle timing configurations are subject to such problems by incorporating, or suggesting the use of, filters to reduce the amount of maintenance and to extend the life of the valves.